Many compositions have heretofore been proposed for skin tanning and some are currently available commercially. It is generally accepted that tanning is caused by the ultra violet component of sunlight and that the degree of tanning of human epidermis by the sun rays depends upon the complexion of the individual. Also, while tanning of the skin is not fully understood, it is generally believed that it results from the formation of melanin, a skin pigment, migration of the melanin to the surface of the skin and its oxidation darkening (see U.S. Pat. No. 3,988,437).
The degree to which an individual is tanned upon exposure to sunlight or artificial sources of ultra violet light depends upon the duration, intensity and exposure to sunlight or such sources. The ultra violet energy which is absorbed by the skin can produce an erythemal reaction (redness) of the skin. Therefore, an attempt at getting a deeper or more intense tan by prolonged exposure to sunlight or other artificial sun sources can cause excessive redness or sunburn of the skin. In order to alleviate redness or sunburn of the skin, some tanning compositions include conventional sun protection ingredients or so-called "sun blockers", which filter out the ultra violet component of the sun rays. While the presence of such ingredients in the tanning composition offer some protection against erythemal reaction in the skin, it also prevents quick tanning because considerable portion of the ultra violet lights are filtered out by these ingredients. Thus, using tanning compositions containing sun blockers permit prolonged exposure to sun without the danger of sunburn, but the skin will not tan faster or deeper by the application of such compositions.
Several recent patents have disclosed various skin tanning compositions. For example, U.S. Pat. No. 3,988,437 issued Oct. 26, 1976 discloses a suntan composition which contains a fluorescent compound for protection against sunburn and to promote tanning.
U.S. Pat. No. 4,434,154 issued Feb. 28, 1984 discloses a tanning and ultra violet screening composition. The composition comprises dihydroxyacetone, octyldimethyl PABA, water oil and surfactant. The surfactants are sodium alkylsulfates wherein the alkyl group contains 8 to 16 carbon atoms.
U.S. Pat. No. 4,714,609 discloses a skin tanning composition comprising a vanillin as the active natural ingredient to accelerate the tanning process.
U.S. Pat. No. 4,781,914 issued Nov. 1, 1988 discloses a sunscreen and moisturizer composition containing polyglycerol-8-oleate for imparting moisture resistance or substantivity to the composition.
U.S. Pat. No. 4,783,332 issued Nov. 8, 1988 discloses a skin tanning composition comprising various ingredients including tyrosine or tyrosine precursor to panthenol and ethoxylated glycerides esterified with fatty acids as described therein.
In a paper published in 1987, Dr. Christine Jaworsky has disputed the claims of many producers of sun tan products who have claimed that their products contain active ingredients which accelerate the tanning process. So far as it is known, there is not available, at the present, a suitable tanning composition which satisfies the consumers' desire for quicker, deeper and more intense tan. See American Academy of Dermatology, Vol. 16 (1987), page 34.
It is therefore an object of this invention to provide a tanning composition which accelerates the skin tanning process.
It is also an object of this invention to provide such tanning compositions which promote and accelerate tanning of the skin without the need for prolonged exposure to harmful sun rays.
It is a further object of this invention to provide tanning compositions which produce a deeper and more intense tan of the skin rapidly and uniformly on the skin.
The foregoing and other advantageous features of the present invention will be more fully appreciated from the ensuing detailed description.